Last week the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention announced a pause on the distribution and use of Johnson and Johnson’s COVID vaccine. The pause amid reports that 6 women who had received the vaccine had developed rare blood clots. The concern this has brought up around J&J’s vaccine mirrors earlier concerns raised in relation to the vaccine produced by AstraZeneca. Vaccine safety is a focus of this episode of Stats and Stories with guest Dr. Susan Ellenberg. Dr. Ellenberg is a Professor of Biostatistics, Medical Ethics and Health Policy, in the Perelman School of Medicine at the University of Pennsylvania, Her research interests have focused on issues in the design and analysis of clinical trials, and on assessment of medical product safety. She is an associate editor of Clinical Trials as well as of the Journal of the National Cancer Institute.